Ordinary Van Hove singularities have been observed in the context of Lifshitz transitions in many materials including cuprate and iron based superconductors, cobaltates, \(\text{Sr}_{2} \text{RuO}_{4}\)  and heavy fermion systems [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}. With the recent advances in the experimental methods of tuning materials and improved resolutions of various spectroscopic probes (including angle resolved photoemission spectroscopy (ARPES)), there is both an increasing interest and emerging avenues for the investigation of the presence and consequence of exotic band geometry in real materials. This is particluarly true for HOVHS, which have been linked with the unusual magnetic and thermodynamic behaviour of \(\mathrm {Sr_3 Ru_2 O_7}\)  [11]}, twisted bilayer graphene near magic angle, close to half filling [12]}, [13]}, [14]}, the recently proposed unusual quantum phase referred to as `supermetal', which has diverging susceptibilities without the presence of any long range order [15]}, the distinct Landau level spectrum of biased bilayer graphene [16]} and the `extended' Van Hove singularity in both doped graphene [17]} and highly overdoped graphene [18]}. More recently, HOVHS have been reported in the kagome superconductors[19]}, [20]}, [21]}, [22]}, and may be relevant to the observed phases of doped Bernal bilayer graphene  [23]}.
